The present invention relates to a rod for rotating bands of rods (rod-bands) for agricultural machines (harvesting machines), especially for screening rod-bands. The present invention also relates to a method for producing such a rod.
Rod-bands are used, for example, to convey farm produce, such as potatoes, whereby the produce is transported such that it is resting on the rods, and whereby dirt, rocks and the like can fall through between the rods, so that already during the transport a sorting and crude or initial cleaning of the material being transported takes place. Conventionally, a rod-band comprises two spaced-apart, endless, flexible, pull resistant belts that are made of rubber reinforced by load carriers, and that can rotate upon suitable driving, support and guide rollers and that are interconnected by rods that are parallel to one another.
Pursuant to the conventional construction, the rods of a rod-band can be made entirely of steel. However, such a rod-band is very heavy. By substituting light composite materials for steel the weight of a rod-band can be significantly reduced. With such rods, the rod body comprises a straight rod made of a solid yet lightweight material, such as glass fiber reinforced polymeric material, that is secured to the belts with the aid of metal sleeves that are disposed at the ends of the rods, whereby the ends of each rod are inserted well into the sleeves, where it is held by crimping, while the overhanging ends of the sleeves are pressed flat and are provided with holes for the securement to the belts via rivets or the like. Unfortunately, in operation such rod-belts have exhibited a number of drawbacks. For example, there exists the danger that a sleeve can twist or deform, especially in the region that is pressed flat or in the overlapping region between the pressed-flat portion and the sleeve-like portion that receives the rod body. The connection between the sleeve and the rod body can become loose. The thickness of the sleeves is too low for a countersinking of the rivet heads, so that on that side of the sleeve that faces away from the belt it is not possible to provide a smooth surface. The rods can be connected with the belts only at their ends; the securement of further belts between the edge belts is not possible. In some applications, bent securement elements are desirable for the rods so that a rod could be disposed in a plane that lies above or below the plane determined by the belts. However, such a bent configuration is not possible with a rod of glass fiber reinforced polymeric material that is held at its ends with sleeves.
These drawbacks can be avoided only partially with a known rod of the aforementioned type where the first, flat length portion of the securement pieces is a solid part produced from a solid rod by forging (see DE 200 11 436 U1). With this known rod, the rod body is accommodated by the second, sleeve-like length portion. The second length portion can be formed by a separately produced sleeve that is fixedly connected with the first length portion by clamping or welding. However, it can also be formed by a blind hole in a solid rod, and can monolithically merge into the first length portion. In all cases the manufacture of the securement pieces involves considerable expense.
It is therefore an object of the present invention to provide a rod of the aforementioned general type where the connection between the rod bodies and the belts can be produced not only so as to withstand stress but also with low expense, and whereby such a connection can be disposed not only at the ends of the rods but also in the middle of a rod.